http://news.bbc.co.uk/1/hi/world/8157939.stm A civilian helicopter has crashed in southern Afghanistan, killing at least 16 people, a military official has told the BBC. The helicopter crashed at the Kandahar airfield, Nato's largest base in southern Afghanistan, apparently as it was trying to take off. Reports from Moscow say the helicopter was a Russian-built Mi-8. The crash is the second in a week. Six passengers died when a helicopter came down in Helmand province on Tuesday. 'Not shot down' Russia's Interfax agency quoted a spokesman for Russia's Federal Air Transportation Agency (Fata) as saying the aircraft was a Russian-built Mi-8 transport helicopter. Fata said it was owned by the Russian air company Vertikal-T. The nationalities of the dead are not yet known. A statement from the International Security Assistance Force said: "A civilian contracted helicopter crashed during take-off from Kandahar airfield. "Emergency personnel are on the scene. There was no indication of the cause of the accident but insurgent action has been ruled out." The dead in Tuesday's crash in Helmand were all civilians. That helicopter crashed near the Sangin military base, with local people saying it had been shot down by insurgents. Six Ukrainian crew members of the Mi-26 helicopter died, along with an Afghan boy on the ground.